Just use a counter that is incremented each time the refresh been called:
<script type="text/javascript">
var numberOfRefreshes = 0;
var auto_refresh = 0;
function refresh_question(){
var url = "/question.do";
jQuery('#question').load(url, function myFunction(reponse, status, xhr){
numberOfRefreshes++;
if(numberOfRefreshes == 10)
{
clearInterval(auto_refresh);
}
}).fadeIn("slow");
}
auto_refresh = setInterval(refresh_question, 4000);
</script>